Home Forums Hunting & Shooting AR and Tactical Rifles 18 inch rifle length piston build?

Debating rebuilding my AR15 in 5.56 to use a short stroke piston instead of DI gas. Barrel currently on the rifle is an 18" Faxon with a rifle length DI gas system. Been eyeing the superlative arms kits, and I know for a while people considered anything shorter than 20 inchest to be too short for the rifle length DI gas. Would I run into issues with reliability if I changed over to a short stroke piston setup on that same barrel?

There are a gazillion 18" rifle gas guns & most all of them, if set up right, run absolutely just fine.

Get the gas port right, the BCG & the buffer & spring all set up right & there's not a problem with any decent ammo.

If you get a barrel from a source that hasn't a clue on the gas port size & makes it too small, you could run into issue.

If the port is around .098" - .103", it should be fine; I used them with ports down to as small as .093" with no problem.

No need to dink with a piston system unless you just want to.

MM

It's mostly I want to. Gas port I believe is .102".

Well have at it then, but 18" DI rifle gas guns run just fine.

MM

I went to pistons on my most used rifles simply because I hate cleaning BCGs with a passion.

So much so that now I just strip them down and throw them in the pin cleaner.

Come out spotless.

You guys clean BCG’s?